Package org.apache.derbyDemo.vtis.core

Class FlatFileVTI

java.lang.Object

org.apache.derby.vti.VTITemplate

org.apache.derby.vti.StringColumnVTI

org.apache.derbyDemo.vtis.core.FlatFileVTI

All Implemented Interfaces:

AutoCloseable, ResultSet, Wrapper, org.apache.derby.vti.AwareVTI

Direct Known Subclasses:

LineListVTI, PropertyFileVTI, SubversionLogVTI

public abstract class FlatFileVTI
extends org.apache.derby.vti.StringColumnVTI

This VTI makes a table out of the records in a flat file. This is an abstract class. Child classes are responsible for implementing the following methods which parse and advance the file:

• parseRow() - Parses the next record of the file into an array of Strings, one for each column.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.derby.vti.VTITemplate

org.apache.derby.vti.VTITemplate.ColumnDescriptor

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	_closed
private File	_file
private FileReader	_fileReader
private int	_lineNumber
private LineNumberReader	_lineReader
private String[]	_row
private String	_textFileName

Fields inherited from interface java.sql.ResultSet

CLOSE_CURSORS_AT_COMMIT, CONCUR_READ_ONLY, CONCUR_UPDATABLE, FETCH_FORWARD, FETCH_REVERSE, FETCH_UNKNOWN, HOLD_CURSORS_OVER_COMMIT, TYPE_FORWARD_ONLY, TYPE_SCROLL_INSENSITIVE, TYPE_SCROLL_SENSITIVE

Constructor Summary

Constructors

Constructor	Description
FlatFileVTI(String[] columnNames, String textFileName)	Build a StringColumnVTI with the given column names

Method Summary

Modifier and Type	Method	Description
void	close()
protected int	getLineNumber()	Get the current line number.
ResultSetMetaData	getMetaData()
protected String	getRawColumn(int columnNumber)	Get the string value of the column in the current row identified by the 1-based columnNumber.
protected String	getTextFileName()	Get the name of the file being read.
boolean	next()
protected abstract String[]	parseRow()	Parse the next chunk of text, using readLine(), and return the next row.
protected String	readLine()	Read the next line from the file and return it.
protected SQLException	wrap(String message, Throwable t)	Wrap an exception in a SQLException.
protected SQLException	wrap(Throwable t)	Wrap an exception in a SQLException.

Methods inherited from class org.apache.derby.vti.StringColumnVTI

findColumn, getAsciiStream, getBigDecimal, getBinaryStream, getBlob, getBoolean, getByte, getBytes, getClob, getColumnCount, getColumnName, getDate, getDouble, getFloat, getInt, getLong, getShort, getString, getTime, getTimestamp, setColumnNames, wasNull

Methods inherited from class org.apache.derby.vti.VTITemplate

absolute, afterLast, beforeFirst, cancelRowUpdates, clearWarnings, deleteRow, first, getArray, getArray, getAsciiStream, getBigDecimal, getBigDecimal, getBigDecimal, getBinaryStream, getBlob, getBoolean, getByte, getBytes, getCharacterStream, getCharacterStream, getClob, getConcurrency, getContext, getCursorName, getDate, getDate, getDate, getDouble, getFetchDirection, getFetchSize, getFloat, getHoldability, getInt, getLong, getNCharacterStream, getNCharacterStream, getNClob, getNClob, getNString, getNString, getObject, getObject, getObject, getObject, getObject, getObject, getRef, getRef, getReturnTableSignature, getRow, getRowId, getRowId, getShort, getSQLXML, getSQLXML, getStatement, getString, getTime, getTime, getTime, getTimestamp, getTimestamp, getTimestamp, getType, getUnicodeStream, getUnicodeStream, getURL, getURL, getWarnings, insertRow, isAfterLast, isBeforeFirst, isClosed, isFirst, isLast, isWrapperFor, last, moveToCurrentRow, moveToInsertRow, notImplemented, previous, refreshRow, relative, rowDeleted, rowInserted, rowUpdated, setContext, setFetchDirection, setFetchSize, unwrap, updateArray, updateArray, updateAsciiStream, updateAsciiStream, updateAsciiStream, updateAsciiStream, updateAsciiStream, updateAsciiStream, updateBigDecimal, updateBigDecimal, updateBinaryStream, updateBinaryStream, updateBinaryStream, updateBinaryStream, updateBinaryStream, updateBinaryStream, updateBlob, updateBlob, updateBlob, updateBlob, updateBlob, updateBlob, updateBoolean, updateBoolean, updateByte, updateByte, updateBytes, updateBytes, updateCharacterStream, updateCharacterStream, updateCharacterStream, updateCharacterStream, updateCharacterStream, updateCharacterStream, updateClob, updateClob, updateClob, updateClob, updateClob, updateClob, updateDate, updateDate, updateDouble, updateDouble, updateFloat, updateFloat, updateInt, updateInt, updateLong, updateLong, updateNCharacterStream, updateNCharacterStream, updateNCharacterStream, updateNCharacterStream, updateNClob, updateNClob, updateNClob, updateNClob, updateNClob, updateNClob, updateNString, updateNString, updateNull, updateNull, updateObject, updateObject, updateObject, updateObject, updateRef, updateRef, updateRow, updateRowId, updateRowId, updateShort, updateShort, updateSQLXML, updateSQLXML, updateString, updateString, updateTime, updateTime, updateTimestamp, updateTimestamp

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.sql.ResultSet

updateObject, updateObject, updateObject, updateObject

Field Details

_textFileName

private String _textFileName

_file

private File _file

_fileReader

private FileReader _fileReader

_lineReader

private LineNumberReader _lineReader

_closed

private boolean _closed

_row

private String[] _row

_lineNumber

private int _lineNumber

Constructor Details

FlatFileVTI

public FlatFileVTI(String[] columnNames,
 String textFileName)

Build a StringColumnVTI with the given column names

Method Details

parseRow

protected abstract String[] parseRow()
                              throws SQLException

Parse the next chunk of text, using readLine(), and return the next row. Returns null if the file is exhausted.

Throws:

SQLException

getRawColumn

protected String getRawColumn(int columnNumber)
                       throws SQLException

Get the string value of the column in the current row identified by the 1-based columnNumber.

Specified by:

getRawColumn in class org.apache.derby.vti.StringColumnVTI

Throws:

SQLException

next

public boolean next()
             throws SQLException

Throws:

SQLException

close

public void close()
           throws SQLException

Throws:

SQLException

getMetaData

public ResultSetMetaData getMetaData()
                              throws SQLException

Specified by:

getMetaData in interface ResultSet

Overrides:

getMetaData in class org.apache.derby.vti.VTITemplate

Throws:

SQLException

getLineNumber

protected int getLineNumber()

Get the current line number.

getTextFileName

protected String getTextFileName()

Get the name of the file being read.

readLine

protected String readLine()
                   throws SQLException

Read the next line from the file and return it. Return null if the file is exhausted.

Throws:

SQLException

wrap

protected SQLException wrap(Throwable t)

Wrap an exception in a SQLException.

wrap

protected SQLException wrap(String message,
 Throwable t)

Wrap an exception in a SQLException.